Corrected compiler warnings
MODE-2013 Added the simpler API logger to Connector

The Connector base class now has a 'log()' method that returns the
simpler API Logger class with methods that take only String parameters
(rather than I18n messages used in the internal logger). The internal
logger is still available via the existing and unchanged 'getLogger()'
method. JavaDoc explains the differences between the two.

Also includes a separate commit that corrects quite a few compiler warnings.
MODE-2015 Deprecated the "removeDerivedContentWithOriginal" configuration attribute
MODE-2012 Added test cases

The two test methods do not replicate the reported problem, but they still are useful since they test functionality not previously tested.